This study proposes to use a control-group design to systematically evaluate the preventive effect of a cognitive-behavioral intervention administered in an educational format to medical outpatients at a county hospital. The target of the intervention is unipolar depression. The patients represent primarily low-income and/or minority residents of San Francisco County. Some of the patients are not English-speaking, and thus the intervention will be made available in Spanish and Cantonese as well as English. The sample will consist of 960 participants (320 in each language group) who agree to take part in a course on self-control techniques to cope with depression. One quarter of the sample will be assigned to a no-intervention control condition (80 in each language group), and the rest will be invited to participate in the class (240 in each language group). High non-compliance rates have been experienced by other health educators at the hospital, and ways to reduce drop out rates will be examined for each group. The aims of the study include: 1. To measure primary prevention effects and secondary prevention effects on unipolar depression using symptom scales (the CES-D and the Beck Depression Inventory) and diagnostic interviews (the depression section of the NIMH Diagnostic Interview Schedule). 2. To identify related preventive effects on physical health variables, such as medical clinic visits, emergency room visits, weight, blood pressure, medications prescribed, laboratory tests ordered, and self-reported symptoms.